R.Clausius’s Contribution to the 1st and 2nd Laws of

Thermodynamics

Eri YAGI(Inst. Hist. of Science, NPO GKN Japan) Sept. 21 2009

(PowerPoint made by Mac G4)

Contents • Introduction• Influence(Math) from Clapeyron & Fourier• Clausius’s heat flow calculation (the difference) • Clausius’s 1st and 2nd laws as a related set of equations

(Fig.II-1)• Clausius’s experimental table • Clausius’s special technical terms for mechanical theory of

heart• Conclusions • References and Notes

Fourier’ on Clausius

Clausius’s heat flow calculation(taking the difference)

Clausius’s 1st law (beginning )

Clausius’s experimental table of Carnot’s function C (1850)

Cent.Gr. ℃ C nach Clapeyron

C nach W.Thomson

35,5 0,733 0,728

78,8 0,828 0,814

100 0,897 0,855

156,8 0,930 0,952

Clausius’s special technical terms

German (original term)AequivalentNicht umkehrbare WeiseVerwandlungs WerthUncompensirte

VerwandlungDisgregationEntoropie

English (translation)EquivalentNon reversible way Transformation valueNon compensate transformationDegree of dispersionEntropy

Clausius’s special technical-terms in his papers

(1850-1865) Appearance O 1850 1854 1862 1865

Nicht umkehrbar

X O O O

Verwandlung X O O O

UncompensirteVerwandlung

X O O O

Disgregation X X O O

Entropie X X X O

Aequivalent O O O O

Conclusions

• Through these analyses, I would like to emphasize Clausius’s Role as the first presenter of the 1st and 2nd laws of thermodynamics in an analytical from.

• In addition, Clausius also presented the 1st and 2nd laws in the literary expression through the introduction of the new concept “Entropy(Entropie)” in the field of physics.

The 1st and 2nd laws of thermodynamics in words

• 1. The energy of the universe is constant.

• 2. The entropy of the universe tends to a maximum.

References and Notes

• References: A Historical Approach to Entropy, collected papers of Eri Yagi and her coworkers (International Publishing Institute Tokyo, 2002) and A Supplement. • Notes: The name Entropy was proposed by R.

Clausius as “Entropie” from the Greek language while in China it has been called Shang with one Chinese letter since 1923 (when Planck visited ).

　 火商

Appendix: Clausius’s functional approach to entropy Q/T

(reversible process) • Clausius proposed one “equivalence value” through

two kinds of transformation,e.g.,1st kind is between work and heat, Qf(t)2nd bet. two different temperatures, QF(t1,t2)These two kinds of transformation were treated at the

same time by the use of Carnot cycle.Then the “equivalence value” in functional form was

determined as Q/T ( in 1854)See E.Yagi”Thermodynamics,”p.1177, Companion

Ency. of History of Mth.Sci.(Routledge1994)